Hundreds of people dashed alongside the six half-ton beasts and their accompanying steer through the cobblestone streets of Pamplona in the eighth run.
There were spine-chilling moments when one bull separated from the pack and charged three runners, pinning them against walls and barriers while trying to gore them.
Navarra hospital's Dr Oscar Gorria said two men were gored in the leg.
A Navarra regional government statement identified one as a 24-year-old Australian with the initials, J M. He was gored in the right thigh. It said a 27-year-old Spaniard with the initials E G E suffered three horn wounds. Neither was in serious condition.
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The morning runs are the highlight of the nine-day street-partying festival immortalised in Ernest Hemingway's 1926 novel "The Sun Also Rises."
In the runs, hundreds of people test their speed and bravery by racing the bulls along a 850-meter course from a holding pen to the city's bull ring.
Dozens of people are injured each year in the "encierros," as the runs are called in Spanish, most of them in falls.
Besides the Australian, five Spaniards and one American were gored in this year's festival.
Fifteen people have died from gorings since record-keeping began in 1924.